Problems in receiving data as a client in Python (TCP)

Question

I have a little problem in my client chat app, basically the app crash if I try to do a function that receive data separately from the one that I use to send them. Basically, if I have only this function it works:

def send_message (ip_address, port, message):
      #Connect to the server
      c = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      c.connect((ip_address, port))
      #Convert message in bytes-like object
      message = message.encode("utf8")
      c.send(message)

      #Receive data
      data = c.recv(88888888888888)
      #Decode data from bytes-like object
      data = data.decode("utf8")
      return data

If I try to do two function, it doesn't work, like this:

def send_message (ip_address, port, message):
      #Connect to the server
      c = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      c.connect((ip_address, port))
      #Convert message in bytes-like object
      message = message.encode("utf8")
      c.send(message)

def receive_message (ip_address, port, message):
      #Connect to the server
      c = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      c.connect((ip_address, port))

      #Receive data
      data = c.recv(88888888888888)
      #Decode data from bytes-like object
      data = data.decode("utf8")
      return data

When I try to call the receive_message function from my GUI the app stop working. Hoping someone can help

EDIT: This is the server code:

import socket
import sys
from threading import Thread



def client_thread(conn, ip, port, MAX_BUFFER_SIZE = 4096):

# the input is in bytes, so decode it
input_from_client_bytes = conn.recv(MAX_BUFFER_SIZE)

# decode input and strip the end of line
input_from_client = input_from_client_bytes.decode("utf8").rstrip()

print("Result of processing is: {}".format(input_from_client))

vysl = res.encode("utf8")  # encode the result string
conn.sendall(vysl)  # send it to client
conn.close()  # close connection
print('Connection ' + ip + ':' + port + " ended")

def start_server():

import socket
soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# this is for easy starting/killing the app
soc.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
print('Socket created')

try:
    soc.bind(("127.0.0.1", 12345))
    print('Socket bind complete')
except socket.error as msg:
    import sys
    print('Bind failed. Error : ' + str(sys.exc_info()))
    sys.exit()

#Start listening on socket
soc.listen(10)
print('Socket now listening')

# for handling task in separate jobs we need threading
from threading import Thread

# this will make an infinite loop needed for 
# not reseting server for every client
while True:
    conn, addr = soc.accept()
    ip, port = str(addr[0]), str(addr[1])
    print('Accepting connection from ' + ip + ':' + port)
    try:
        Thread(target=client_thread, args=(conn, ip, port)).start()
    except:
        print("Terible error!")
        import traceback
        traceback.print_exc()
soc.close()

start_server() 

Answer 1

You don't show what's on the other end of your connection. I guess it's something like an echo which responds to received messages.

In the first case you open a single connection, first write to it, then read a response.

In the second case you open two separate connections. You write to the first one socket, read from the second one. Is anyone writing on the second socket? I guess not.